The optics consist of a two-lens Huygens-type eyepiece and one of three multi-lens objectives.
There are three eyepieces included with this instrument. They are engraved "1", "2", and "3".
Three multi-lens objectives are included with this instrument, a low-magnification unmarked objective, one marked "3" and the third marked "5"
The eyepieces are the Huygens-type with the plane surface of both converging lenses facing the operator
Objective "5" disassembled showing the two lens components. This is an achromatic objective.
All eyepieces have a central aperture (arrow) matched i diameter to the front lens element.
Assembled objective No. 5.